Windmill, combining reverse osmosis technology with traditional windmill capabilities, is tested for seawater desalination.
A traditional windmill that drives a pump: This is the simple
concept behind the combination of windmill/reverse osmosis developed by the
Delft University of Technology (TU Delft) in The Netherlands. In this case, it
involves a high-pressure pump that pushes water through a membrane using
approximately 60 bar. The reverse osmosis membrane produces fresh water from
seawater directly. The windmill is suited for use, for instance, by small
villages in isolated, dry coastal areas.
The combination of windmills and
desalination installations already is commercially available. These windmills
produce electricity from wind power; the electricity is stored and subsequently
used to drive the high-pressure pump for the reverse osmosis installation. The
storage of electricity in particular is very expensive. Energy also is lost
In the TU Delft installation, the high-pressure pump is
driven directly by wind power. Water storage can be used to overcome calm
The chosen windmill normally is used for irrigation
purposes. These windmills turn relatively slowly, and also are designed to be
very robust. On the basis of the windmill’s capacity at varying wind speeds, it
is estimated that it will produce 1,320 gallons to more than 2,640 gallons of
fresh water per day: enough drinking water for a small village of 500
inhabitants. A water reservoir will have to ensure that enough water is
available for a calm period lasting up to five days. Three safeguards – in the
event of the installation running dry, a low number of revolutions or a high
number of revolutions – also are performed mechanically so that no electricity
The first prototype has been
built, and already is working at a location near Delft.
This prototype is to be dismantled and transported to Curaçao in early March,
where the concept will be tested on seawater.